Anode Sludge Research Articles

Understanding the Role of the Black Anodic Film in Copper Electrodeposition in Sulfuric Acid Medium: Organic Additives Free Electrolytes

In the process of copper electroplating from a sulfuric acid bath it is well known that the copper anodes must contain a small quantity of phosphorous (CuP) (0.04 to 0.06 %). In the other hand, the electrolyte must contain a small amount of chloride ions (50 to 100 mg/L). The result is the formation on an anodic black film. The latter is essential in the proper functioning of the copper electroplating process. The presence of this black film prevents the formation of anodic sludge which compromises the quality of the copper deposits. The anodic behavior of copper is of great interest not only from the theoretical point of view but also as an important practical problem. The anodic sludge is formed by one of the following mechanisms [1], [2], Eq. (1) which is the disproportionation reaction of the cuprous ions, mechanism 1:2 Cu+ ↔ Cu2+ + Cu (1)Eq. (1) is responsible for the formation of anodic sludges. The mechanism 2 is the preferential dissolution along the intergrain boundaries and the consequent detachment of complete crystal grains from the crystalline structure. The addition of phosphorus as an alloying element during the manufacture of the anodes and the presence of chloride ions in the plating bath result in the formation of the anodic black film which eliminates the possibility of copper anode grains detachment and the alteration of the anodic dissolution mechanism. Copper anode dissolution proceeds under a two steps mechanism described by Eq. (2) and (3):Cu ↔ Cu+ + e- (2)Cu+ -> Cu2+ + e- (3)Both of these reactions take place in the anodic film. In order to move from a bath with additives to a bath without additives, it is essential to answer the following questions: What is the effect of organic additives on the anodic side? What is the optimal concentration range for chloride ions? What is the influence of the grain size of Copper-Phosphorus anodes?The present work deals with a extended characterization of the black anodic film and relevant insights about its formation mechanisms.[1] : ST. RASHKOV and L. VUCHKOV, The Kinetics and Mechanism of The Anodic Dissolution of Phosphorus-Containing Copper in Bright Copper Plating Electrolytes, Surface Technology, 14 (1981) 309 – 321.[2] : G. S. Frankel, A. G. Schrott, H. S. lsaacs, J. Horkans, and P. C. Andricacos, Behavior of CuP and OFHC Cu Anodes under EIectrodeposition Conditions, United States. Department of Energy, Brookhaven National Lab., Upton, NY (United States), 1992. Figure 1

Efficient conversion process and mechanism of bromine in bromine-rich saline wastewater

Bromine resources, widely utilized in basic chemical engineering, are considered non-renewable. A substantial amount of Bromine-Rich Saline Wastewater (BRSW), a hazardous waste, is generated during the smelting process of waste printed circuit boards (WPCBs). The efficient conversion of bromine resources is important in BRSW, which contain high concentrations of bromide ions. This study developed a synergistic treatment method utilizing electrolytic manganese anode sludge (EMAS) achieved efficient conversion of Br− to Br2 in BRSW. Optimal technical parameters are determined through single-factor experiments, and the oxidative acid leaching process was optimized using response surface methodology (RSM). The significant influencing factors for Br− conversion were ranked as acidity > anode mud addition amount > temperature > time, resulting in a bromine conversion efficiency of 96.55%. Kinetic studies of bromine conversion in BRSW during the oxidation-acid leaching process indicated a two-stage process: Stage I being a chemical reaction control model and Stage II being a diffusion control model. The reaction mechanism was elucidated, where H+ initially breaks the Mn-O bond in MnO2, exposing O vacancies and forming Mn4+, leading to a redox reaction between free Br− and Mn4+. This research embodies the concept of synergistic solid waste disposal, achieving cost-effectiveness and streamlined preparation of bromine, and providing technical and theoretical support for bromine resource recovery in BRSW.

A novel three-dimensional biofilm-electrode/anoxic-oxic process for nitrogen and phosphorus removal: Performance, mechanism and microbial community

Traditional anoxic-oxic (AO) process cannot meet increasingly high pollutants emission standards in China. In order to improve removal efficiencies of the pollutants and the electron transfer rate, graphite-graphite electrodes and iron carbon fillers were added into AO reactor to form three-dimensional biofilm electrode/anoxic aerobic reactor (3DBER/AO). Removal efficiencies of the pollutants, sludge properties and microbial community structure were investigated under different current intensities. The results showed that microbial activity and removal efficiencies of the pollutants were the maximum, and mass percentage of Fe reached the highest value of 5.11 % under the current of 40 mA. Excessive or insufficient current intensity could lead to a decrease in sludge activity and removal efficiencies of the pollutants. The removal of nitrogen mainly depended on the nitrification and denitrification of microorganisms, and dissolved phosphorus was removed through chemical precipitation. Current intensity affected microbial communities and biosynthesis. AKYH767 and Saccharmonadales were dominant microorganisms in the cathode and anode sludge, respectively, under the current of 40 mA. However, Azospira and Dechlorobacter were dominant microorganisms in the cathode sludge, and Hydrogenophaga was dominant microorganisms in the anode sludge under the current of 60 mA. These microorganisms were closely related to the removal of organic matter, nitrogen and phosphorus. Therefore, microbial community structure and removal efficiencies of the pollutants could be regulated by controlling the current intensity in the 3DBER/AO process.

POSSIBILIITY OF URANIUM EXTRACTION FROM SPENT NUCLEAR FUEL IN FUSED ELECTROLITES CONTAINING RARE ELEMENTS

Link for citation: Nikitin D.I., Polovov I.B., Rebrin O.I. Possibility of uranium extraction from spent nuclear fuel in fused electrolytes containing rare elements . Bulletin of the Tomsk Polytechnic University. Geo Аssets Engineering, 2023, vol. 334, no. 10, рр. 210-218. In Rus. The relevance of the research is caused by the plans of using electrolytic separation of metalized spent nuclear fuel as a stage in pyrochemical reprocessing of mixed nitride uranium-plutonium fuel. The main aim is to determine the parameters of uranium electrolytic separation from an alloy with simulators of fission products (precious metals and rare earth elements) simulating spent nuclear fuel in salt mixtures based on 3LiCl–2KCl with additives of rare earth element chlorides. Objects: model spent nuclear fuel – uranium alloy with simulators of fission product (precious metals and rare earth elements) with a mass compound of Pd:Ru:Ag:Rh=25:1:3:3, Nd:Ce:La:Pr:Sm:Y=15:10:5:5:5:1). Methods: electrorefining, X-ray fluorescence and X-ray diffraction method of analysis, inductively coupled plasma mass spectrometry, assessment of distribution of components in the system. Results. The data obtained showed that uranium deposits have dendrite formations of alpha-uranium at 550 °C in orthorhombic crystal system toward needle cathode current density. The resulting cathode deposits are free from impurities of ruthenium, rhodium, molybdenum, praseodymium and yttrium. The purification coefficient for palladium reaches 3000, and for silver 1700. Noble metals accumulate in the anode sludge, and even with the complete depletion of the anode material. The concentration of noble metals in the cathode deposit does not exceed 0,0015 wt %. Despite the high concentration of rare-earth chlorides in the electrolyte, which simulates the accumulation of rare-earth ions during repeated reprocessing of spent nuclear fuel, the concentration of rare-earth metals in the cathode product did not exceed 0,007 wt %. During uranium electrowinning from a model spent nuclear fuel in the 3LiCl–2KCl–UCl3 electrolyte (10,1 wt %) with REE chlorides, which imitate their accumulation in the electrolyte during repeated processing, at 550 °C, as well as the initial cathode current density of 0,2 A/cm2, the specific amount of electricity is 1,0 A∙h/cm2. A cathode uranium deposit is released with a current efficiency exceeding 90 % with all anode mass depletion, and purification coefficient 1800 for the sum of precious metals and for the sum of rare earth metals.

Al-rich industrial waste as new alternative of fumed silica for the manufacture of vacuum insulation panels for building energy conservation

Nano-structured fumed silica (FS) is the most used vacuum insulation panel (VIP) core material for building applications. However, the FS VIP core has the majority of the environmental burden associated with conventional VIP manufacture and FS-based VIPs are very expensive. This paper explores aluminium anodizing sludge (ALW), a residue from the aluminium industry, as a new substitute for FS in VIP cores. Al-rich sludge waste is thoroughly characterised, and 100%-based ALW and its hybrid core mixtures with FS are formulated to produce VIPs cores, which are then evaluated. ALW was observed as aggregated clusters of nanosized individual particles in round and smooth-shaped forms typical of hydrated gel-like pure amorphous materials. The microstructure system of the sole ALW VIP core is found to be dissimilar to that of an FS VIP core, with the pore size range of 0.1–0.8 μm for the former and 0.01–0.04 μm for the latter, but the overall volume of large pores being much higher for the FS than ALW cores. The hybridization of ALW and FS resulted in a restructure of the initial ALW core systems. While the thermal conductivity of the ALW VIP core is less proficient than that of the single FS core, the effective thermal conductivity of both ALW50FS50 and ALW25FS75 core compositions at 1 Pa even suppressed that of the sole FS core, presenting 5.8 mW m−1·K−1 against 6.3 mW m−1·K−1 respectively. A life cycle assessment (LCA) study of these hybrid core solutions was also conducted to illustrate the positive environmental benefit of ALW-based VIP compared to FS-based VIP production. The study highlights the potential of using industrial residue ALW in VIP production, contributing to developing more sustainable superinsulation materials.

Influence of alternating electric field on deep dewatering of municipal sludge and changes of extracellular polymeric substance during dewatering

A self-prepared experimental device made of plexiglass with alternating power supply system was used to study the deep dewatering of municipal dewatered sludge. Considering the reduction rate of sludge water content (Wr) as the index, factors affecting enhanced electric settlement of sludge such as exchange electrode method, voltage gradient, sludge thickness, and mechanical pressure were studied, and the dewatering mechanism was elucidated. The single-factor experiment combined with the surface response method based on the Box–Behnken central experimental design was performed. With Wr as the response value, the voltage gradient conditions, time ratio, and sludge thickness were optimized. Pearson correlation analysis showed that the reduction of proteins/polysaccharides was beneficial to improving the sludge dewatering effect. Tightly bound extracellular polymeric substances (TB-EPSs) showed a significant influence on the sludge dewatering effect. Under the action of the external electric field, particles with negative charge moved toward the anode sludge, water with partial positive charge flowed to the cathode, and the sludge cellular structure was damaged. This resulted in the dissolution of a large number of EPSs and the release of bound water. The anode sludge cake got thickened due to the accumulation of the sludge particles, leading to the increase in resistance. The TB-EPS was deconstructed by the ohmic heating to improve the sludge dewatering effect and achieve deep dewatering. Scanning electron microscopy results showed that the drying problem of anode sludge was alleviated during the dewatering process.

Local electrochemical deposition of copper from sulfate solution

Local electrochemical deposition is a type of electroplating used to plate metal locally or form metal objects using electrochemical principles at a short distance from the working electrode. In this work, deposition of the copper spot was modelled using COMSOL software and experimentally tested in copper sulfate electrolyte using soluble copper anode. The working capillary diameter was 4 mm and the interelectrode distance was 5 mm. The deposited copper of 100 µm height was investigated using the 3D-profilometry technique. The geometry of deposited metal was found to be in good accordance with the COMSOL model. The inclusions of anodic sludge were responsible for the surface inhomogeneity of the deposited copper.

Simultaneous degradation of anodic sludge and cathodic refractory pollutant in a MFC powered EF system enhanced by co-addition of lysozyme and 2-bromoethane sulfonate

To enhance simultaneous bioelectrochemical treatment of excess sludge and refractory wastewater, a microbial fuel cell powered electro-Fenton system (MFCⓅEFs) with the co-addition of lysozyme (LZ) and 2-bromoethane sulfonate (BES) into sludge was set up and an in-depth investigation of pollutants degradation, micro-electricity utilization, microbial communities and functional genes was conducted. Experimental results showed a maximum sludge total chemical oxygen demand (TCOD) removal achieved 80.21 % in 25 d with co-addition of 50 mg/gSS LZ and 25 mmol/L BES in anodic chamber of MFCⓅEFs, while the degradation of syringic acid (SA) as a model refractory pollutant reached 97.42 % in cathodic chamber within 25 h, and obtained a 3.35 W/m3 maximum power density. The quantification of micro-electricity utilization revealed that sludge hydrolysis enhanced by LZ could reduce electricity sink, and methanogenesis inhibited by BES could ensure more electrons to be used for exoelectrogenesis. The co-addition of LZ + BES resulted in an increased abundance of exoelectrogens (Pseudomonas, Bacteriodetes, and Chlorobium) and a decreased major methanogenic group by inhibiting gene-function of coenzyme-M. The columbic efficiency of the MFCⓅEFs with co-addition of LZ + BES was increased to 8.31 % (only 4.22 % for control). The complete mineralization of SA in MFCⓅEFs was ascribed to the high generation rates of hydrogen peroxide and free radicals. The results provided a new insight to use in-situ generated micro-electricity from MFCⓅEFs to realize simultaneous treatment of excess sludge and residual refractory pollutant in the secondary effluent of wastewater treatment plant.

SNF processing electrochemical operations: liquid-metal and salt medium purification

The paper investigates the process of regeneration of a liquid metal medium used in the pyroelectrochemical reprocessing of spent mixed uranium-plutonium nitride fuel produced by a fast neutron reactor. The investigation concerns the interaction of liquid cadmium with sludge formed during the anodic dissolution of ceramic nitride pellets in a 3LiCl-2KCl melt medium as well as the possibility of its purification by filtration from individual metal fission products. Anode sludge is represented by fission products of the platinum group, zirconium, molybdenum and technetium. It was determined by scanning electron microscopy that the metal product is composed of several intergrowth phases. It was found that upon contact of a polymetallic alloy simulating anode sludge with a melt, the liquid metal phase is saturated to 0.025 wt% of Pd, 0.01 wt% of Rh for 50 hours at 500 °C, while zirconium forms an insoluble dispersed intermetallic compound ZrCd3. Powders of molybdenum and technetium, which are not wetted with cadmium, can be completely removed using a filter mesh of plain weaving of the P-200 type. It is also possible to remove zirconium from anodic cadmium by filtration. The filtration efficiency of ruthenium and palladium powders did not exceed 54.3 and 13.1 wt%, respectively, due to partial dissolution and thinning of particles, which will lead to saturation of the liquid metal phase and the need to purify it by alternative methods.

Recycling of Gold From Waste Electrical and Electronic Equipment by Electrorefining of Copper

This article presents the methods of processing gold-plated pins from, among others, used computer equipment and discusses the research results on the recovered metal. Due to the relatively small structure of the pins and the fact that the gold layer is only a few microns thick, recovering gold from them constitutes a significant challenge. On the other hand, gold is a precious metal which enables the collective removal of other metals to obtain pure gold. The suggested method involves compacting the gold-plated pins into an anode form and carrying out the electro-refining process. Metals, such as copper, tin and iron, pass into the anode sludge from which they can be extracted or serve as a commercial intermediate sold to smelter plants. The anode sludge was melted in the flame of an oxy-acetylene torch in a graphite crucible by adding borax. As a result of the melting, several metallic precipitates were obtained. Then they were hot-incorporated into a sample with a diameter of 30 mm and a height of 12 mm. Eventually, a pure gold alloy sample was obtained, which contains Cu 40.69%, Sn 9.61% and Au 48.58%.

Simultaneous Degradation of Anodic Sludge and Cathodic Refractory Pollutant in a Mfc Powered Ef System Enhanced by Co-Addition of Lysozyme and 2-Bromoethane Sulfonate

Simultaneous Degradation of Anodic Sludge and Cathodic Refractory Pollutant in a Mfc Powered Ef System Enhanced by Co-Addition of Lysozyme and 2-Bromoethane Sulfonate

Microwave-assisted recovery of lead from electrolytic manganese anode sludge using tartaric acid and NaOH

ABSTRACT In this study, a new metallurgical system for treating electrolytic manganese anode sludge by microwave roasting and alkaline leaching system was developed, and the lead leaching behaviour was studied. The XRD results show that Pb in anode sludge is mainly in the form of PbSO4 after microwave roasting at 850°C, as a result, the leaching rate of Pb is improved. The results show that the leaching rate of lead can reach 93.89% under the conditions of liquid–solid ratio of 7:1, leaching time of 30 min, leaching temperature of 40°C, and the concentration of sodium hydroxide of 8%. The addition of tartaric acid can further improve the lead leaching rate, FT-IR analysis showed that the coordination form of lead and tartaric acid. Lead and tartaric acid ions (L) form three coordination compounds, PbL, Pb2L2 and Pb2L3, which can only exist in alkaline solution.

Separation of zinc and iron from secondary manganese sulfate leachate by solvent extraction

Purification of concentrated manganese sulfate solution by solvent extraction is discussed in this paper. The use of bis(2-ethylhexyl)hydrogen phosphate(D2EHPA) and bis(2,4,4-trimethylpentyl)phosphinic acid (BTMPPA) was studied in removal of impurities from zinc electrowinning anode sludge leachates. Over 99% of zinc and iron were removed by both extractants at around pH3 in two mixer-settlers operating in continuous countercurrent mode at a solvent-to-feed (S/F) ratio of 0.43 and T = 22 ± 1 °C. BTMPPA had higher selectivity for zinc and iron over manganese than D2EHPA under all experimental conditions. Extraction of manganese was typically below 10% and can be limited by crowding the extractants, since the fraction of manganese in both loaded extractants was decreased by decreasing organic to aqueous volumetric ratio (O/A). A significant amount of the co-extracted Mn was recovered by selective stripping with 0.5 M sulfuric acid. Extraction by BTMPPA was more sensitive to pH adjustment than extraction by D2EHPA. Increasing the mean residence time in mixer from 3.6 min to6.0 min improved the removal of zinc and iron with BTMPPA but the change in residence time had little or no effect on zinc and iron removal with D2EHPA.

Iron and Aluminium Production Wastes as Exclusive Components of Alkali Activated Binders—Towards a Sustainable Alternative

The sustainability of resources is becoming a worldwide concern, including construction and building materials, especially with the alarming increase rate in global population. Alternative solutions to ordinary Portland cement (OPC) as a concrete binder are being studied, namely the so-called alkali-activated cements (AAC). These are less harmful to the environment, as lower CO2 emissions are associated with their fabrication, and their mechanical properties can be similar to those of the OPC. The aim of developing alkali-activated materials (AAM) is the maximization of the incorporated recycled materials, which minimises the CO2 emissions and cost, while also achieving acceptable properties for construction applications. Therefore, various efforts are being made to produce sustainable construction materials based on different sources and raw materials. Recently, significant attention has been raised from the by-products of the steelmaking industry, mostly due to their widespread availability. In this paper, ladle slag (LS) resulting from steelmaking operations was studied as the main precursor to produce AAC, combined with phosphating bath sludge—or phosphate sludge (PS)—and aluminium anodising sludge (AS), two by-products of the surface treatment of metals, in replacement rates of 10 and 20 wt.%. The precursors were activated by two different alkaline solutions: a combination of commercial sodium hydroxide and sodium silicate (COM), and a disposed solution from the cleaning of aluminium extrusion steel dies (CLE). This study assesses the influence of these by-products from the steelmaking industry (PS, AS and CLE) on the performance of the alkali-activated LS, and specifically on its fresh and hardened state properties, including rheology, heat of hydration, compressive strength and microstructure and mineralogy (X-ray diffraction, scanning electron microscopy coupled with energy dispersive spectroscopy and Fourier transform infra-red. The results showed that the CLE had no negative impact on the strength of the AAM incorporating PS or/and AS, while increasing the strength of the LS alone by 2×. Additionally, regardless of the precursor combination, the use of a commercial activator (COM) led to more fluid pastes, compared with the CLE.

Physical-chemical processes of sustainable construction materials structure formation with iron ore processing tailings and aluminum anodizing sludge

To replace completely natural raw materials were developed new sustainable concrete-like construction composites from 10 − 40% iron ore tailings, 10–35% aluminum anodizing sludge, 25–30% concrete waste, and 15–25% lime production waste with mechanical and physical properties that meet the requirements of the Brazilian standards. The composition’s axial compression resistance reached 4.49 MPa on the 3rd day and 11.24 MPa on the 730th day of cure. All mechanical, physical, and chemical properties of newly developed composites from these industrial wastes met Brazilian standards for producing construction materials like ecological. Dilatation coefficient values varied between 0.95 and 2.35% on the 3rd day of cure, and it ranged from 1.35 to 2.05% on the 730th day. The apparent specific mass increased during two years from 3.38 − 3.67% to 3.47–3.75. Such properties met the requirements of Brazilian standards for producing sustainable road bases, bricks, and blocks. The studies of structure formation processes during 730 days of outdoor cure showed the synthesis of mainly amorphous sol–gel new formations with a slight inclusion of crystalline carbonate content. The main novelty of this research study is the scientifically and experimentally proven possibility to produce new environmentally clean construction composites only from four types of hazardous industrial waste to replace traditional natural raw materials like sand, gravel, crushed stone. The use of this laboratory study’s results at the industrial level will reduce the irreversible destruction of nature by quarries of construction materials, noticeably improving our planet’s sustainability.

Recycling glass-polishing sludge and aluminum anodising sludge in polyurethane and cement composites: fire performance and mechanical properties

This article aims to study the mechanical strength and fire resistance of polyurethane/cement (PuCem) composites containing glass sludge and sludge from aluminum anodizing. Scanning electron microscopy (SEM) results showed that the replacement of 24.5% of the cement with sand (San), aluminum anodizing (Aas), or glass-polishing sludge (Gla) maintained the alveolar structure in the composites. Also, energy-dispersive X-ray spectroscopy and FTIR analyses showed that the cement hydration reaction forms hydrated aluminates and silicates. ANOVA–Tukey tests showed that the PuCemAas composites’ areas are significantly different from those of PuCemGla and PuCemSan, which are similar to each other. The compressive strength decreases upon replacing cement with the aggregates. The TGA thermograms were similar for the four composites and the polyurethane matrix. The specimens were declassified in the vertical and horizontal position (UL-94). Thus, the composites were an alternative for reducing the use of raw materials from non-renewable sources.

ELIMINATION OF VALUE ADDED TAX ON MINING (ANODA SLUDGE) IN INDONESIA

The obstacles in the processing and refining of mining materials in Indonesia are making theneed for support from various sectors, not least related to the purchase of anode sludge whichcontributes to taxes. Hence, this study purposed to analyse the elimination of value added taxon mining (anode sludge). This study used the legal research method which was conducted bytwo approaches namely the statutory and the conceptual approach. The results showed that ineliminating the Value Added Tax, the government could use the regular-end function.Moreover, the elimination of VAT can provide facilities for the development of the smelterindustry. On the other hand, the government can also use the basis that the tax collectionrequirements must not interfere with the country's economic development. Thus, it can beconcluded that the elimination of Value Added Tax related to mining goods (anode sludge) isan important study. Since it is able to provide the space for the development of the industry inmanaging their respective businesses.

Coupled with EDDS and approaching anode technique enhanced electrokinetic remediation removal heavy metal from sludge.

In this work, the novel technology was used to remove heavy metal from sludge. The coupled with biodegradable ethylenediamine disuccinic acid (EDDS) and approaching anode electrokinetic (AA-EK) technique was used to enhance heavy metal removing from sludge. Electric current, sludge and electrolyte characteristics, heavy metal removal efficiency and residual content distribution, and heavy metal fractions percentage of variation were evaluated during the electrokinetic remediation process. Results demonstrated that the coupled with EDDS and AA-EK technique obtain a predominant heavy metal removal efficiency, and promote electric current increasing during the enhanced electrokinetic remediation process. The catholyte electrical conductivity was higher than the anolyte, and electrical conductivity of near the cathode sludge achieved a higher value than anode sludge during the coupled with EDDS and AA-EK remediation process. AA-EK technique can produce a great number of H+, which caused the sludge acidification and pH decrease. Cu, Zn, Cr, Pb, Ni and Mn obtain the highest extraction efficiency after the coupled with EDDS and AA-EK remediation, which were 52.2±2.57%, 56.8±3.62%, 60.4±3.62%, 47.2±2.35%, 53.0±3.48%, 54.2±3.43%, respectively. Also, heavy metal fractions analysis demonstrated that the oxidizable fraction percentage decreased slowly after the coupled with EDDS and AA-EK remediation.

Selective Recovery of Manganese from Anode Sludge Residue by Reductive Leaching

Manganese-containing anode sludge is a common side-product in the electrowinning of zinc. The anode sludge consists mainly of oxidized manganese, but also lesser amounts of lead, calcium, and other minor metals. The impurities present in the anode sludge mandate new recycling strategies for its efficient use. This work demonstrates a novel method for selective manganese recovery from lead- and calcium-bearing manganese oxide solid residue. Leaching with sulfuric acid in the presence of a selected reducing agent, such as hydrogen peroxide or citric acid, yields a concentrated MnSO4 solution with high selectivity over calcium and lead. Manganese yields up to 98% can be obtained. Minimization of calcium and lead in final manganese product can be accomplished with the correct choice of leaching conditions. Alongside manganese sulfate solution, leaching residue with high content of lead and silver was also formed.

Nuclear measurement in Pyro-processed wastes

Nuclear fissile material was analyzed for the waste produced in the pyro-process. Nuclear waste is produced at each stage in the pyro-process, spent fuel head-end, major group recovery area and TRU-RE process. Each yields waste of different material composition and properties. Chemical analysis is basically determined for the measurement of nuclear material content. However, the possibility of non-destructive analysis techniques were examined as an additional and supplementary way for cost effectiveness and time saving in the nuclear material analysis. Examinations were undertaken on RE-salt waste, anode sludge, and hull. A gamma peak of Cm244 and Pu239 was simulated for the RE waste. The peak was well distinguishable in the waste. The linearity in the gamma measurement was approved with the content increase in the plutonium isotope. For fissile assay in anode sludge and hull, a neutron method was suggested. From the simulation results, a probable technique was recommended for plutonium content assay in each waste of the pyro-process. An accurate fissile assay will contribute to an increased safeguards for the pyro-processing system and international credibility for the reuse of fissile materials in the fuel cycle.